Confuciusornis, from the early Cretaceous of China,
is the oldest known beaked bird, and one of the oldest known
birds -- only Archaeopteryx, from the late Jurassic of
Germany, is older. Confuciusornis is a member of the Confuciusornithidae, the sister-group to the clade composed of Enantiornithes + Ornithurae (includes modern birds).

About the Species

This specimen is preserved in lithographic stone. This is the case for most fossil birds, because their very delicate bones, many of which are hollow, can only survive the fossilization process in environments producing particularly fine-grained stone. Unfortunately, preservation in slabs such as this obscures the entire ventral side of the specimen. However, CT scanning enables us to digitally erase the lithographic stone, revealing the underside of these specimens with unprecedented detail. Examples are shown below.

The specimen was scanned by Richard Ketcham and Timothy Rowe on 16-17 July 1998 along the long axis of the slab encasing it for a total of 618 slices, each slice 0.5 mm thick, with an interslice spacing of 0.45 mm (for a slice overlap of 0.05 mm).

About the Scan

Literature

Chiappe, L. M., J. Shu-an, J. Qiang, and M. A. Norell. 1999. Anatomy and systematics of the Confuciusornithidae (Theropoda: Aves) from the late Mesozoic of northeastern China. Bulletin of the American Museum of Natural History 242:3-89.